Fencing materials and methods have developed over hundreds and thousands of years and continue to evolve. Fencing is used to contain livestock, to maintain a separation between species, to exclude livestock and other animals from crops, etc. Fence posts and fencing material between posts may be constructed of a variety of materials including wood, steel, composites, and others. A combination often-used in modern farm and ranching operations is steel fence posts supporting various types and numbers of strands of wire strung between posts. Straight or barbed wire may be used, for example. Barbed wire may deter animal crossing as it is sharp and may be painful for an animal attempting to cross a barbed-wire fence. Another technique that may be effective using a small number of strands is electric fencing. One or more electrically conductive strands are energized at a high voltage but are current-limited to create a strong electric shock without harming an animal attempting to cross. One complicating factor with electric fencing is the need to electrically insulate each energized strand of wire and any conductive retaining wires used to fasten the energized strand at each fence post to prevent current leakage to ground through the fence post.
The steel t-post is a fence post designed for wire fencing. FIG. 1 is a prior-art diagram of an example section 100 of a fencing t-post. Generally speaking, the t-post takes its name from its cross-sectional shape. A flat vertical member 110 orthogonally abuts a cross member 120 approximately halfway across the width of the cross member 120 at a junction 130. The junction 130 runs the length 140 of the section oft-post 100.
Some t-post designs may also have a series of nubs (e.g., the nub 150) protruding from the cross member 120 on the side of the cross member 120 opposite the junction 130 of the vertical member 110 and the cross member 120. Some t-posts may be designed with extensions 120A and 120B of the cross member 120 extending from the flat vertical member 110 at an angle other than 90 degrees. Other t-posts may be designed with the extensions 120A and 120B curved slightly toward the nubs 150, forming a concave area populated by the nubs 150 along the length of the t-post. Each of several fencing wires is generally positioned at the bottom of an appropriate nub. The fencing wire is fastened at that position along the length 140 using a separate retaining wire wrapped around the fence wire and the edges of the vertical member 110 and the two edges of the cross member 120. The nubs in conjunction with the retaining wire thus alleviate vertical slippage of the fencing wire along the length of the t-post.
In some cases, t-posts are used to implement electric fences. In that case, an insulator is required to be fitted to each section oft-post at points touched by an electric fence wire to be energized and/or by a conductive retaining wire wrapped around the fencing wire and the fence post. Insulators may be fabricated from various electrically insulating materials including glass and plastic. Plastic insulators are known which snap around the two edges of the extensions 120A and 120B of the cross member 120 and extend outward from the wire surface side 170 of the t-post 100. Such insulators thus form a lever arm outward from the t-post surface 170. Livestock may come into contact with and dislodge such “extension type” insulators from the t-post due to the lever arm effect.
“Sleeve” type insulators are also known. Such insulators slide down from the top of the fence post during installation and prior to fastening the fencing wires to the fence post.